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library(ggplot2)
#数据集必须是data.frame格式#
head(mtcars)
##                    mpg cyl disp  hp drat    wt  qsec vs am gear carb
## Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
## Datsun 710        22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
## Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
## Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
## Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1
#ggplot2画图，首先要定义数据和坐标，其它东西例如标题，颜色，形状用图层的方法慢慢往上加。
p <- ggplot(mtcars, aes(x=mpg, y=wt, colour=cyl))
p

#可以看到我们定义了横坐标为mpg,纵坐标为wt，颜色按照cyl分类。cyl在这里就相当于一个标签。也可以写成p <- ggplot(mtcars, aes(mpg, wt, colour=cyl))
p1 <- p+geom_point() #geom_point()为通过”+”以图层的方式加入点的几何对象,geom_point()表示点图
p1

#在geom_point()中，我们可以加入一些参数
p2 <- p+geom_point(color="blue")
p2

p3 <- p+geom_point(aes(color="blue"))#最后一行语句为错误的映射关系, 在aes中, color = “blue”的实际意思是把”blue”当为一个变量, 用这个变量里的数据去关联图形属性中的参数, 因为”blue”只含有一个字符变量, 默认情况下为离散变量, 按默认的颜色标度标记为桃红色
p3

pp <- ggplot(mtcars, aes(x = mpg, y = wt, color = factor(gear)))
#设定默认的映射关系,颜色改成离散型变量（不是渐变色了）
pp + geom_point()

#沿用默认的映射关系来绘制散点图
pp + geom_point(aes(shape = factor(carb)))

#添加图层中的shape的映射关系，点图中不同变量用不同的符号
pp + geom_point(aes(y = carb))

#修改默认的y的映射关系, 注意图中y轴名称仍然以默认的wt表示
pp + geom_point(aes(color = NULL))

 #删除默认的color映射关系
p4 <- pp+geom_boxplot()#箱线图
p4

p5 <- pp+geom_boxplot(aes(fill=factor(gear)))#填充颜色
p5

library(ggplot2)
library(plotly)#引入新的R包可以做成可交互的数据可视化图
## 
## Attaching package: 'plotly'
## The following object is masked from 'package:ggplot2':
## 
##     last_plot
## The following object is masked from 'package:stats':
## 
##     filter
## The following object is masked from 'package:graphics':
## 
##     layout
pp <- ggplot(mtcars, aes(x = mpg, y = wt, color = factor(gear)))
p3 <- pp +geom_point()
ggplotly(p3)
library(ggsci)#ggsci这个包可以按照期刊风格改变配色
p7 <-p3 +scale_color_npg()#nature系列配色
p7

pp+geom_boxplot()

p8 <- pp+geom_boxplot()+scale_color_npg()
p8

p9 <- pp + scale_color_aaas() +geom_boxplot()
p9

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